Thermoelectric modules, used in thermoelectric apparatus and in thermoelectric devices using such thermoelectric modules

Abstract

A thermoelectric module comprises an odd number of thermoelements (1a, 2a, 1b) connected electrically in series and disposed thermally in parallel. The electrical current flowing through a heat exchanger (9) is conducted into the module by metallic members (8a, 8b) and by first and second types of connectors (4a, 4b and 6a, 6b).

What is claimed: 
     
       1. A thermoelectric module comprising a plurality of thermoelements, associated electrical connectors and cooperating heat exchangers adapted to form thermoelectric devices made of stacks of active thermoelectric units formed by a plurality of said modules and each associated with a heat exchanger through which flows a fluid to be cooled or a fluid acting as a cold source, and with a heat exchanger through which flows a fluid to be warmed or a fluid acting as a warm source, wherein said thermoelectric module includes an odd number (2x+1) of thermoelements, wherein (x) is a positive, non-zero integer; said thermoelements being connected electrically in series and thermally in parallel and being secured to corresponding electrical connectors, said electrical connectors being secured to inner face of two electrically conducting members which are in electrical and thermal contact, through the external faces thereof, with the heat exchangers and which act also as electrical terminals for module current flow, said electrical connectors which are secured to thermoelements being either two connectors of a first type secured, respectively, to a face of an inlet thermoelement and a face of an outlet thermoelement and in thermal and electrial contact with a respective one of said electrically conducting members so as to provide a module current inlet and outlet, or connectors of a second type, which are 2x in number, and are respectively secured in two groups of x connectors to the inner faces of said members in thermal contact therewith but electrically insulate therefrom by at least one insulating layer disposed on the surfaces of the second type connectors facing the inner faces of said members, said second type connectors serving to connect two by two the faces of the thermal elements which do not provide the current inlet and outlet so as to provide, in combination with the thermoelements which provide the current inlet and outlet and are secured to the two first type connectors, a preferential path for the current wherein the current is forced to flow through the entire plurality of thermoelements between the current inlet and outlet without flowing through said members, said module including (x+1) thermoelements of a P or N-type and x thermoelements of the other P or N-type, and the current inlet and outlet being provided by two thermoelements of the type of the said x+1 thermoelements, so as to provide one or the other of two kinds of modules which are functionally equivalent to single N and P-type thermoelements, at least one of the two external faces of said electrially conductive members in thermal and electrical contact with the heat exchangers having a non-planar shape cooperating with a reciprocally shaped base member of the corresponding heat exchanger. 
     
     
       2. A module according to claim 1, wherein two external faces of said members in thermal and electrical contact with said heat exchangers are portions of concave spherical surfaces, cooperating with reciprocally shaped spherical surfaces of the base members of said heat exchangers. 
     
     
       3. A module according to claim 1, wherein the two external surfaces of said members in thermal and electrical contact with the heat exchangers are portions of concave cylindrical surfaces with the axes thereof extending either parallel or orthogonal, and being located in parallel planes cooperating with reciprocally shaped cylindrical surfaces of base members of the corresponding heat exchangers. 
     
     
       4. A module according to claim 1, wherein the arrangement of the 2x+1 thermoelements is of a circular geometry, said two members providing the electrical and thermal contact with heat exchangers also having a circular geometry. 
     
     
       5. A module according to claim 1 wherein the arrangement of the 2x+1 thermoelements is of rectangular geometry, the thermoelements being disposed in a chessboard pattern, the two members making the electrical and thermal contact with heat exchangers also having a rectangular geometry. 
     
     
       6. A module according to claim 1, wherein the arrangement of the 2x+1 thermoelements is a geometry wherein the said two members providing the electrical and thermal contact with a heat exchanger have a regular or non-polygonal shape. 
     
     
       7. A module according to claim 1, wherein the electrical insulation between the second type connectors and the said members is provided by a thin insulating layer disposed on the faces of said second type connectors facing the inner faces of said members, the thermal contact and mechanical connection being provided a further layer of an adhesive or a solder. 
     
     
       8. A module according to claim 1 wherein the electrical insulation between the connectors of the second type and the said members is provided by a thin insulating layer disposed on the faces of the second type connectors facing said members, said layer comprising an adhesive which provides the thermal contact with and the mechanical connection to said members. 
     
     
       9. A module according to claim 1, wherein one of the two external faces of said members in thermal and electrical contact with a heat exchanger is planar, the other face being a portion of convex or concave spherical surface of a base member of the other heat exchanger. 
     
     
       10. A module according to claim 1, wherein two external faces of said members in thermal and electrical contact with said heat exchangers are portions of convex spherical surfaces, cooperating with reciprocally shaped spherical surfaces of the base members of said heat exchangers. 
     
     
       11. A module acording to claim 1 wherein one of the two external faces of said members in thermal and electrical contact with the heat exchangers is planar, the other being a portion of convex or concave cylindrical surface, having an axis extending parallel to the plane of the planar surface, and co-operating with a reciprocally shaped cylindrical surface of the corresponding heat exchanger. 
     
     
       12. A module according to claim 1, wherein the two external surfaces of said members in thermal and electrical contact with the heat exchangers are portions of convex cylindrical surfaces with the axes thereof extending either parallel or orthogonal, and being located in parallel planes cooperating with reciprocally shaped cylindrical surfaces of base members of the corresponding heat exchangers. 
     
     
       13. A module according to claim 1 wherein the cross sectional areas provided for current flow are optimized for each of the two N and P-types of thermoelements and for the operating conditions, such optimization being carried out according to the thermoelectric characteristics of both N and P-types. 
     
     
       14. A module according to claim 13 wherein the thermoelectric characteristics of the two N and P-types of thermoelements are substantially equal and the cross sectional areas provided for current flow are equal for both N and P-types of thermoelements. 
     
     
       15. A thermoelectric device comprising stacks of electrically conducting heat exchangers and active thermoelectric units in thermal and electrical contact with said heat exchangers, said active units comprising both N-type modules and P-type modules and said modules each comprising an odd number (2x+1) of thermoelements, wherein (x) is a positive, non-zero integer; said thermoelements being connected electrically in series and thermally in parallel and being secured to corresponding electrical connectors, said electrical connectors being secured to inner face of two electrically conducting members which are in electrical and thermal contact, through the external faces thereof, with the heat exchangers and which act also as electrical terminals for module current flow, said electrical connectors which are secured to thermoelements being either two connectors of a first type secured, respectively, to a face of an inlet thermoelement and a face of an outlet thermoelement and in thermal and electrical contact with a respective one of said electrically conducting members so as to provide a module current inlet and outlet, or connectors of a second type, which are 2x in number, and are respectively secured in two groups of x connectors to the inner faces of said members in thermal contact therewith but electrically insulated therefrom by at least one insulating layer disposed on the surfaces of the second type connectors facing the inner faces of said members, said second type connectors serving to connect two by two the faces of the thermal elements which do not provide the current inlet and outlet so as to provide, in combination with the thermoelements which provide the current inlet and outlet and are secured to the two first type connectors, a preferential path for the current wherein the current is forced to flow through the entire plurality of thermoelements between the current inlet and outlet without flowing through said members, said module further including (x+1) thermoelements of a P or N-type and x thermoelements of the other P or N-type, and the current inlet and outlet being provided by two thermoelements of the type of the said x+1 thermoelements, so as to provide one or the other of two kinds of modules which are functionally equivalent ot single N and P-type thermoelements. 
     
     
       16. A module according to claim 15, wherein the arrangement of the 2x+1 thermoelements is of a circular geometry, said two electrically conducting members providing the electrical and thermal contact with heat exchangers also having a circular geometry. 
     
     
       17. A module according to claim 15 wherein the arrangement of the 2x+1 thermoelements is of rectangular geometry, the thermoelements being disposed in a chessboard pattern, the two members making the electrical and thermal contact with heat exchangers also having a rectangular geometry. 
     
     
       18. A module according to claim 15 wherein the arrangement of the 2x+1 thermoelements is a geometry wherein the said two members providing the electrical and thermal contact with a heat exchanger have a regular or non-polygonal shape. 
     
     
       19. A module according to claim 15, wherein the electrical insulation between the second type connectors and the said members is provided by a thin insulating layer disposed on the faces of said second type connectors facing the inner faces of said members, the thermal contact and mechanical connection being provided a further layer of an adhesive or a solder. 
     
     
       20. A module according to claim 15 wherein the electrical insulation between the connectors or the second type and the said members is provided by a thin insulating layer disposed on the faces of the second type connectors facing said members, said layer comprising an adhesive which provides the thermal contact with and the mechanical connection to said members. 
     
     
       21. A module according to claim 15 wherein at lesat one of the two external faces of said electrically conductive members in thermal and electrical contact with the heat exchangers having a non-planar shape cooperating with a reciprocally shaped base member of the corresponding heat exchanger.